Apparatus and method for inverse telecine with local video de-interlacing

ABSTRACT

The present invention relates to systems and methods for inverse telecine or video de-interlacing for picture quality improvement on set-top-box and TV products. The system comprises a film mode detector at the picture or sequence level, a global mixed video and film content detector at the region, picture, or sequence level on top of the detected film content, and a local video content detector at pixel level on top of the detected mixed video and film content. Inverse telecine processing is applied on detected film content fading in with a locally de-interlaced local video content. The invention further provides an apparatus and method for globally detecting mixed video and film content at region, picture, or sequence level. Such apparatus and method comprise a plurality of detectors for robustness and increased detection accuracy.

RELATED APPLICATIONS

The present application relates to co-pending U.S. patent applicationSer. No. 12/978,154, filed on Dec. 23, 2010, and assigned AttorneyDocket No. 10-SIN-058, and U.S. patent application Ser. No. 13/174,194,filed concurrently, and assigned Attorney Docket No. 10-SIN-1052.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an apparatus and method forinverse telecine and video de-interlacing, and, more particularly, to acadence detection system and method that is programmable to improvepicture quality of broadcasted videos with mixed video and film modesources in TV and set-top-box (STB) products.

2. Relevant Background

Interlaced video was used for cathode ray tube (CRT) displays and isfound throughout a number of broadcasting formats. Modern videodisplays, e.g., liquid crystal displays (LCD) and plasma displays, donot operate in interlaced mode. Therefore, de-interlacing circuitry isneeded in set-top-box (STB)/TV to de-interlace video into progressivevideo that can be played on modern video displays.

Currently, there are a number of different source formats. Video formatsusually display at 50 or 60 frames per second; film formats are commonlycaptured at 24 or 25 frames per second. Because of the difference inframe rate, telecine is applied to a film source video in order toproperly display the film source video on a video display. Reversetelecine may be applied to the telecined film source video to recover ahigher quality non-interlaced video to display on a compatible device,such as a modern video display.

Cadence detection involves finding the source format of a sequence ofvideo fields or detects the absence of motion between frames (stillpictures) and determines whether a video is originally from a video orfilm source that had interlacing or telecine applied. De-interlacing orinverse telecine can be appropriately applied to the video after cadencedetection in order to remove the selected filtering.

Mixed video and film sources are commonly seen in broadcasted videos,e.g., graphics overlap over video or scrolling text on a film-sourcevideo. A global film mode detection and global switching between inversetelecine and video de-interlacing mode is suboptimal in this case as itwould leave either compromised vertical resolution or unhandledfeathering/comb artifacts on the part of the unremoved interlace ortelecine filtering.

U.S. Patent Publication No. 2007/0291169, “Region-Based CadenceDetector,” discusses blocked based film/video decision and switching. Aframe is segmented into a pre-set number of regions (or clusters ofblocks) for cadence and phase tracking. A block level inverse telecineor video de-interlacing is applied to the mixed source video. However,region-based cadence detection suffers in picture quality and robustnessdue to artifacts from the switching.

Accordingly, there is a need in the art for increasing detectionaccuracy to prevent feather/comb artifacts on moving video object areasand increasing robustness of film and video mode detection to improvepicture quality of mixed cadence sources.

SUMMARY OF THE INVENTION

Accordingly, the invention is directed to an apparatus and method forinverse telecine or video de-interlacing for picture quality improvementthat substantially obviates one or more of the problems due tolimitations and disadvantages of the related art.

Briefly stated, the present invention involves film and video modedetections at both a global and local level. Film mode can be detectedat a global level. Confidence of detection is increased by introducing atwo-step check for mixed video content, one at a global level when filmmode is detected and another at a local level when mixed video contentis detected at a global level. Mixed video content detection methods canbe further separately optimized for global and local detection.

BRIEF DESCRIPTION

FIG. 1 is an exemplary diagram of a video processing system and methodfor inverse telecine and/or video de-interlacing according to anembodiment of the invention;

FIG. 2 is an exemplary diagram of an embodiment of a global videochecker according to an embodiment of the invention;

FIG. 3 is an exemplary diagram of a global video checker for cadencewith repeat field according to an embodiment of the invention;

FIG. 4 is a diagram illustrating an example window used by a repeatfield motion detector;

FIG. 5 is an exemplary diagram of a global video checker for cadencewithout repeat field unit according to an embodiment of the invention;

FIG. 6 is an exemplary diagram of a feathering detector according to anembodiment of the invention;

FIG. 7 is a diagram illustrating a processing window of a verticalfrequency analyzer;

FIG. 8 is an exemplary diagram of a motion adaptiveness unit accordingto an embodiment of the invention;

FIG. 9 is a diagram illustrating an example neighborhood window used ina vertical frequency post-processing unit;

FIG. 10 is an exemplary diagram of a tail detector according to anembodiment of the invention;

FIG. 11 is an exemplary diagram of a global detail estimator accordingto an embodiment of the invention;

FIGS. 12( a) and 12(b) are examples of inter-field motions and globaldetail levels for explanation of an embodiment of global detailestimator;

FIG. 13 is an exemplary diagram of a tail analysis unit according to anembodiment of the invention; and

FIG. 14 is a diagram illustrating example neighborhood windows used intail post-processing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention are hereafter described in detailwith reference to the accompanying figures. Although the invention hasbeen described and illustrated with a certain degree of particularity,it is understood that the present disclosure has been made only by wayof example and that numerous changes in the combination and arrangementof parts can be resorted to by those skilled in the art withoutdeparting from the spirit and scope of the invention.

The following description with reference to the accompanying figures isprovided to assist in a comprehensive understanding of exemplaryembodiments of the present invention as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the embodiments described hereincan be made without departing from the scope and spirit of theinvention. Also, descriptions of well-known functions and constructionsare omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but are merely used by theinventor to enable a clear and consistent understanding of theinvention. Accordingly, it should be apparent to those skilled in theart that the following description of exemplary embodiments of thepresent invention are provided for purposes of illustration only and notfor the purpose of limiting the invention as defined by the appendedclaims and their equivalents.

The present invention involves film and video mode detections at both aglobal and local level. Film mode can be detected at a global level.Confidence of detection is increased by introducing a two-step check formixed video content, one at a global level when film mode is detectedand another at a local level when mixed video content is detected at aglobal level. Mixed video content detection methods can further beseparately optimized for global and local detection.

Reference will now be made in detail to an embodiment of the presentinvention, an example of which is illustrated in the accompanyingdrawings.

FIG. 1 illustrates a video processing system and method for inversetelecine and/or video de-interlacing according to an embodiment of theinvention.

The video processing system according to an embodiment of the inventioncomprises global film mode detection 10, global video de-interlacing 20,global video checker 30, global inverse telecine 40, local videodetection 50, and local fading between inverse telecine and videode-interlacing 60.

Global film mode detection 10 detects film mode globally at picture orsequence level. An example of global film mode detection 10 is disclosedin U.S. patent application Ser. No. 12/978,154. Global videode-interlacing 20 is applied when no film content is detected globallyby global film mode detection 10.

If global film mode is detected by global film mode detection 10, globalvideo checker 30 detects video mode at a region, picture or sequencelevel. Global inverse telecine 40 is applied when there is no mixedvideo and film content detected.

If global video mode is detected by global video checker 30, indicatingthat there is mixed video and film content detected, local videodetection 50 detects local video mode at the pixel level. An example oflocal video detection 50 is [disclosed in U.S. patent application Ser.No. ______, also known as Attorney Docket No. 10-SIN-1052]. Pixel levellocal fading between inverse telecine and video de-interlacing 60 isapplied based on result of local video detection 50.

One of ordinary skill in the art would appreciate that by introducing atwo step check for mixed video content, one at the global level whenfilm mode is detected and the other at the local level when mixed videocontent is detected globally, confidence of detection is increased.Further, the two step check process could be separately optimized forglobal and local detection respectively.

The video processing system according to an embodiment of the inventionis configured to receive a video signal from DVD, cable or satellite TVchannel broadcasters, or internet video providers, and outputs aprocessed video signal for optimal display on modern flat screen panels.

FIG. 2 illustrates a global video checker according to an embodiment ofthe invention.

The global video checker unit receives a video input signal 100, acadence signal 700 from a global film mode detector in a videoprocessing system such as global film mode detection 10 in FIG. 1, andoutputs a video fallback mode flag 900. The global video checkercomprises a global video check for cadence with repeat field unit 200, aglobal video check for cadence without repeat field unit 400, amultiplexer 600 coupled to the global video check for cadencewith/without repeat field units 200 and 400, and a temporal control unit800 coupled to multiplexer 600.

The global video check for cadence with repeat field unit 200, describedin detail below with reference to FIG. 3, receives the video inputsignal 100 and outputs a video fallback mode flag 300 for cadences withrepeat field.

The global video check for cadence without repeat field unit 400,described in detail below with reference to FIG. 5, receives the videoinput signal 100 and outputs a video fallback mode flag 500 for cadenceswithout repeat field.

The multiplexer 600 selects either video fallback mode flag 300 or 500according to the type of the cadence, i.e., if the cadence is withrepeat field or not, and outputs a video fallback mode flag 650indicating the existence of mixed video and film content. The cadencesignal 700 could be provided by an external global film mode detector ina video processing system such as global film mode detection 10 inFIG. 1. By adopting two separate methods of global video check forcadences with and without repeat field, the global video check unitcould detect video mixed with various cadences; thus, the robustness ofthe detection could be improved.

In order to avoid temporal instability, the temporal control unit 800receives the video fallback mode flags 650 from a plurality of fields,and outputs the temporally converged video fallback mode flag 900.

FIG. 3 illustrates a global video check for cadence with repeat fieldunit according to an embodiment of the invention.

The global video check for cadence with repeat field unit 200 receivesthe video input signal 100, and provides a video fallback mode flag 300for cadences with repeat field. According to one embodiment, the globalvideo checker for cadence with repeat field unit 200 comprises aninter-frame motion detector 210, which could usually be shared with anexternal global film mode detector or an external de-interlacer, arepeat field motion detector 220 coupled to inter-frame motion detector210, a summing unit 230 coupled to repeat field motion detection 220,and a video fallback mode decision unit 240 coupled to summing unit 230.

The repeat field motion detector 220 receives a repeat field flag 250from an external global film mode detector and a plurality ofinter-frame motion values 215 in a neighborhood window, compares theseinter-frame motion values with a motion threshold when the current fieldis a repeat field, and provides a detected repeat field motion flag forthe center pixel of the neighborhood window based on the density of themotion in this local window. An example method of the repeat fieldmotion detector 220 is illustrated with Equation 1 (a) to (d), with theneighborhood window used in this example method shown in FIG. 4.

$\begin{matrix}{{vfreq}_{k} = \left\{ \begin{matrix}{{freq}_{k,1} - {freq}_{k,2}} & {{fielddiff}_{k} \geq {MonotoneTh}} \\0 & {otherwise}\end{matrix} \right.} & {{Eqn}\mspace{14mu} 1(a)} \\{{k = 0},1,2} & \; \\{where} & \; \\{{freq}_{k,1} = {\sum\limits_{i = 0}^{3}\left( {{\left( {y_{k + i} - {mean}_{k}} \right) \cdot \left( {y_{k + i + 1} - {mean}_{k}} \right)} < 0} \right.}} & {{Eqn}\mspace{14mu} 1(b)} \\{{freq}_{k,2} = {\sum\limits_{i = 0}^{2}\left( {{\left( {y_{k + i} - {mean}_{k}} \right) \cdot \left( {y_{k + i + 2} - {mean}_{k}} \right)} < 0} \right)}} & {{Eqn}\mspace{14mu} 1(c)} \\{{mean}_{k} = {\left( {{\left( {y_{k} + y_{k + 2} + y_{k + 4}} \right) \times 2} + {\left( {y_{k + 1} + y_{k + 3}} \right) \times 3} + 6} \right)/12}} & {{Eqn}\mspace{14mu} 1(d)}\end{matrix}$

The summing unit 230 receives a plurality of the detected repeat fieldmotion 225, accumulates them in a block, a region, or a field, andprovides a repeat field motion sum 235 for the video fallback modedecision unit 240.

The video fallback mode decision unit 240 receives the summed repeatfield motion 235, compares it with a user defined threshold, and outputsa binary signal indicating if mixed video and film content exists in thetargeted block, region, or field. This binary signal is the videofallback mode flag 300.

FIG. 5 illustrates a global video check for cadence without repeat fieldunit according to an embodiment of the invention.

The global video check for cadence without repeat field unit 400receives the video input signal 100, and provides a video fallback modeflag 500 for cadences without repeat field. In one embodiment, theglobal video checker for cadence without repeat field 400 comprises afeathering detector 410, a tail detector 440, and a video fallback modedecision unit for cadences without repeat field 490 coupled to thefeathering detector 410 and the tail detector 440.

The feathering detector 410, described in detail below with reference toFIG. 6, receives a plurality of fields of the video input signal 100,and provides a summed feathering value 430 to the video fallback modedecision unit 490.

The tail detector 440, described in detail below with reference to FIG.10, receives a plurality of fields of the video input signal 100, andprovides a summed tail value 485 to the video fallback mode decisionunit 490.

The video fallback mode decision for cadence without repeat field unit490 receives the summed feathering value 430 and the summed tail value485, compares them with their respective user defined thresholds, anddecides if mixed video and film content exist based on the result of thefeathering detector 410 and/or the result of the tail detector 440.

FIG. 6 illustrates a feathering detector according to an embodiment ofthe invention. Feathering detector 410 further comprises an optionalinter-frame motion detector 210, an optional comparator 216 coupled tooptional inter-frame motion detector 210, a field buffer 218 coupled tocomparator 216, a multiplexer 110, a vertical frequency analysis unit420 coupled to multiplexer 110, a motion adaptiveness unit 422 coupledto comparator 216 and field buffer 218, a vertical frequencypost-processing unit 424 coupled to motion adaptiveness unit 422, and asumming unit 426 coupled to vertical frequency post-processing unit 424.

The inter-frame motion detector 210, which could usually be shared witha global film mode detector or a de-interlacer in a video processingsystem as in FIG. 1, receives a previous field and a next field of thevideo input signal 100 at times t−1 and t+1, respectively, and providesan inter-frame motion signal 215.

In one embodiment, the optional comparator 216 compares the inter-framemotion signal 215 with a pre-defined motion threshold, and provides abinary motion value 217 to the field buffer 218 for cost savingpurposes. In another embodiment without comparator 216, the field buffer218 would have to store the inter-frame motion values at their fullprecision and this could lead to more hardware costs.

The multiplexer 110 receives the previous field and the next field ofthe video input signal 100, selects one of them as the coupling fieldsignal 120 according to the phase information 710 received from anexternal global film mode detector.

The vertical frequency analysis unit 420 receives a plurality of pixelsfrom the current field and the coupling field of the video signal 100,and provides the detected feathering values 421. An example method ofthe vertical frequency analysis is illustrated with reference toEquation 2 (a) to (f). The used input pixel window, including the evennumbered pixels from the current field and the odd numbered pixels fromthe coupling field, is shown in FIG. 7.

$\begin{matrix}{{vfreq}_{k} = \left\{ \begin{matrix}{{freq}_{k,1} - {freq}_{k,2}} & {{fielddiff}_{k} \geq {MonotoneTh}} \\0 & {otherwise}\end{matrix} \right.} & {{Eqn}\mspace{14mu} 2(a)} \\{{k = 0},1,2} & \; \\{where} & \; \\{{freq}_{k,1} = {\sum\limits_{i = 0}^{3}\left( {{\left( {y_{k + i} - {mean}_{k}} \right) \cdot \left( {y_{k + i + 1} - {mean}_{k}} \right)} < 0} \right)}} & {{Eqn}\mspace{14mu} 2(b)} \\{{freq}_{k,2} = {\sum\limits_{i = 0}^{2}\left( {{\left( {y_{k + 1} - {mean}_{k\;}} \right) \cdot \left( {y_{k + i + 2} - {mean}_{k}} \right)} < 0} \right)}} & {{Eqn}\mspace{14mu} 2(c)} \\{{mean}_{k} = {\left( {{\left( {y_{k} + y_{k + 2} + y_{k + 4}} \right) \times 2} + {\left( {y_{k + 1} + y_{k + 3}} \right) \times 3} + 6} \right)/12}} & {{Eqn}\mspace{14mu} 2(d)} \\{and} & \; \\{{fielddiff}_{k} = {{{{\left( {y_{k} + y_{k + 2} + y_{k + 4}} \right) \times 2} - {\left( {y_{k + 1} + y_{k + 3}} \right) \times 3}}}/12}} & {{Eqn}\mspace{14mu} 2(e)} \\{{vf} = \left\{ \begin{matrix}{\max \left( {{vfreq}_{0},{vfreq}_{1}} \right)} & {{currfield} = {top}} \\{\max \left( {{vfreq}_{1},{vfreq}_{2}} \right)} & {{currfield} = {bottom}}\end{matrix} \right.} & {{Eqn}\mspace{14mu} 2(f)}\end{matrix}$

FIG. 8 illustrates a motion adaptiveness unit according to an embodimentof the invention. The motion adaptiveness unit 422 receives the detectedfeathering value 421, the recursive inter-frame motion values 217 and219 at times t and t−1, respectively, and provides a moving featheringsignal 423. The motion adaptiveness unit 422 further comprises a maxoperator 427 and a multiplexer 428 coupled to max operator 427. The maxoperator 427 receives the recursive inter-frame motion values 217 and219, and outputs the maximum motion value 429 to the multiplexer 428.The multiplexer 428 then outputs the detected feathering value 421 ifthe maximum motion value 429 is classified as motion, or else outputs‘0’ as the moving feathering value 423. The motion adaptiveness unit 422improves the accuracy of the feathering detection since video pixelsexhibit feathering artifacts only at moving areas.

The vertical frequency post-processing unit 424 in FIG. 6 receives aplurality of the moving feathering values 423 in a local neighborhoodwindow and provides a post-processed feathering value 425. An examplemethod of the vertical frequency post-processing is illustrated withreference to Equation 3 (a) to (e), with the used input neighborhoodwindow as shown in FIG. 9.

$\begin{matrix}{{vf}^{''} = \left\{ \begin{matrix}{vf}^{\prime} & {{\left( {{vf}_{0,0}^{\prime} > {VFTh}} \right)\&}\mspace{14mu} \begin{pmatrix}\left. \begin{pmatrix}{\left( {{sum} \geq {VFSumTh}} \right)\&} \\\left( {{rcnt} = {true}} \right)\end{pmatrix} \right| \\\left( {c_{0} \geq \left( {{VFColTh} \times 4} \right)} \right)\end{pmatrix}} \\0 & {otherwise}\end{matrix} \right.} & {{Eqn}\mspace{14mu} 3(a)} \\{where} & \; \\{{sum} = {\sum\limits_{j = {- 2}}^{2}c_{j}}} & {{Eqn}\mspace{14mu} 3(b)} \\{c_{j} = {\sum\limits_{i = {- 2}}^{2}{vf}_{i,j}^{\prime}}} & {{Eqn}\mspace{14mu} 3(c)} \\{and} & \; \\{{rcnt} = \begin{pmatrix}{{{\left( {r_{- 2} \geq {VFRowTh}} \right)\&}\mspace{14mu} \left( {r_{- 1} \geq {VFRowTh}} \right)}\&} \\{{{{\left( {r_{0} \geq {VFRowTh}} \right)\&}\mspace{14mu} \left( {r_{- 1} \geq {VFRowTh}} \right)}\&}\mspace{14mu} \left( {r_{2} \geq {VFRowTh}} \right)}\end{pmatrix}} & {{{Eqn}\mspace{11mu} 3(d)}\;} \\{r_{i} = {{\sum\limits_{j = {- 2}}^{2}{\left( {{vf}_{i,j}^{\prime} > {VFTh}} \right)\mspace{14mu} i}} \in \left\lbrack {{- 2},2} \right\rbrack}} & {{Eqn}\mspace{14mu} 3(e)}\end{matrix}$

FIG. 10 illustrates tail detector 440 according to an embodiment of theinvention.

The tail detector 440 comprises an optional pre-filter 101, an optionalinter-field motion detector 103 coupled to pre-filter 101, a globaldetail estimator 450 coupled to inter-field motion detector 103, a tailanalysis unit 460 coupled to global detail estimator 450, a tailpost-processing unit 481 coupled to tail analysis unit 460, and asumming unit 483 coupled to tail post-processing unit 481.

The optional pre-filter 101 is often able to be shared with a globalfilm mode detector in a video processing system as described in FIG. 1,and is configured to correct the phase of the input video signalvertically based on the top/bottom parity of the field and provides aphase-corrected video signal 102.

The inter-field motion detector 103 is also able to be shared with aglobal film mode detector in a video processing system as described inFIG. 1, and is configured to receive a plurality of fields of thephase-corrected video signal 102, and provide the detected inter-fieldmotion between consecutive fields 104 to the global detail estimator450.

The global detail estimator 450, described in detail below withreference to FIG. 11, is configured to receive a plurality of theexisting inter-field motion signal between consecutive fields 104, andprovides an estimation of the global detail level 459 for the tailanalysis.

The tail analysis unit 460, described in detail below with reference toFIG. 13, receives a plurality of fields of the video signal 102 and theglobal detail level 459 and provides a global detail adaptive tailsignal 480. Being global detail level adaptive, the tail analysis isrobust to vertical details of the picture content which often affectsthe accuracy of the tail motion detection. In a preferred embodiment,the video signal 102 is received from an optional pre-filter 101.

The tail post-processing unit 481, described in detail below withreference to FIG. 14, receives the tailing motion 480. Optionally, italso receives the feathering value 421 to aid the tailing motiondetection and provides a post-processed tail motion 482.

The summing unit 483 then accumulates the post-processed tail motion ina block, region, or field and outputs the summed value 485 to the videofallback mode decision for cadence without repeat field 490.

Referring now to FIG. 11, an exemplary diagram of a global detailestimator is depicted in accordance with an embodiment. The globaldetail estimator 450 comprises an average operator 451, a min operator453 coupled to average operator 451, and a thresholding unit 455 coupledto min operator 453. The average operator 451 receives the existinginter-field motions 104 at times t−3 and t−1 and outputs the average ofthem 452. The min operator 453 receives the average of the inter-fieldmotion at times t−3 and t−1 and the inter-field motion at time t−2 andprovides the minimum value 454 of the two, namely m12_static. Finally,the thresholding unit 455 compares the minimum value 454 with a set ofthresholds such as the HighDetailTh 456 and the MidDetailTh 457 andprovides the classified global detail level 459.

As understood by one of ordinary skill in the art, the inter-fieldmotions 104 of a film source exhibit high when the two fields are fromdifferent progressive frames and exhibit low when the two fields arefrom the same progressive frame. The calculated min value 454(m12_static) is actually the lower value of the inter-field motions,which also represents the vertical detail level of a picture. FIGS. 12(a) and (b) illustrate examples of inter-field motions along the time andthe respective m12_static. The example in FIG. 12 (a) could be from apicture with a lot of vertical details whereas the example in FIG. 12(b) could be from a picture with little vertical details, as could betold by the value of m12_static.

FIG. 13 is an exemplary diagram of tail analysis unit 460 according toan embodiment of the invention. The tail analysis unit 460 comprises twomultiplexers 461 and 462, two adders 465 and 466 coupled to multiplexers461 and 462, respectively, multiplexer 478, a comparator and sign unit469 coupled to adder 465 and multiplexer 478, a sign unit 471 coupled toadder 466, a sign comparator 473 coupled to comparator and sign unit 469and sign unit 471, an absolute operator 475 coupled to adder 465, and amultiplexer 477 coupled to sign comparator 473 and absolute operator475.

The multiplexer 461 receives the video signals 102 at times t−1 and t+1,and selects one of them as the coupling field 463 of the current fieldat time t according to the phase information 710 from an external globalfilm mode detector. The multiplexer 462, in contrary to 461, selects theother field that has not been selected by 461, which is the field 464.

The adder 465 provides the difference 467 between the field at time tand the field 463. The other adder 466 provides the difference 468between the field 464 and the field at time t.

The comparator and sign unit 469 compare the difference 467 with athreshold IntraFrameMotTh 479 and decide the sign 470, where thethreshold 479 is selected by the multiplexer 478 from a set ofthresholds based on the global detail level 459. The sign unit 471decides the sign of the difference 468.

The sign comparator 473 compares the received signs 470 and 472 andprovides output 474 indicating whether the differences 467 and 468 areof the same sign.

The multiplexer 477 provides the absolute value 476 of the difference467 from the absolute operator 475 if the differences 467 and 468 are ofthe same sign and outputs zero when they are not.

One of ordinary skill in the art would appreciate that the signcomparator 473 with the comparator and sign unit 469 and the sign unit471 is used to detect tailing motion, indicated by the same sign of themotion differences 467 and 468. Tailing motion is especially useful todetect continuous motion in one direction and, hence, false alarms ofmotion, i.e. those motions in random directions, would be excluded fromthe detected tail 480.

FIG. 14 illustrates example neighborhood windows used in the tailpost-processing unit 481 of FIG. 10. An example method of the tailpost-processing is illustrated with Equation 4 (a) to (e). One ofordinary skill in the art would appreciate that the tail post-processingmethod is used to detect the strength and the density of the tail motionand of the feathering value in a local neighborhood window for are-enforced decision of tail motion.

$\begin{matrix}{{tail}^{\prime} = \left\{ \begin{matrix}1 & {{\left( {t > 0} \right)\&}\mspace{14mu} \left( {v > 0} \right)} \\0 & {otherwise}\end{matrix} \right.} & {{Eqn}\mspace{14mu} 4(a)} \\{where} & \; \\{t = {{{{\left( {{tail}_{i,j} > 0} \right)\&}\mspace{14mu} \left( {{\sum\limits_{i = {- 2}}^{2}r_{i}} \geq {TailCntTh}} \right)}\&}\; \left( {{\sum\limits_{i = {- 2}}^{2}\left( {r_{i} > 0} \right)} \geq {TailCntInRowTh}} \right)}} & {{Eqn}\mspace{14mu} 4(b)} \\{r_{i} = {{\sum\limits_{j = {- 2}}^{2}{\left( {{tail}_{i,j} > 0} \right)\mspace{14mu} i}} \in \left\lbrack {{- 2},2} \right\rbrack}} & {{Eqn}\mspace{14mu} 4(c)} \\{and} & \; \\{v = {{\left( {{\sum\limits_{i = {- 2}}^{2}s_{i}} \geq {TailVFCntTh}} \right)\&}\mspace{20mu} \left( {{\sum\limits_{i = {- 2}}^{2}\left( {s_{i} > 0} \right)} \geq {TailVFCntInRowTh}} \right)}} & {{Eqn}\mspace{14mu} 4(d)} \\{s_{i} = {{\sum\limits_{j = {- 2}}^{2}{\left( {{vf}_{i,j} > {TailVFTh}} \right)\mspace{14mu} i}} \in {\left\lbrack {{- 2},2} \right\rbrack.}}} & {{Eqn}\mspace{14mu} 4(e)}\end{matrix}$

Although the invention has been described and illustrated with a certaindegree of particularity, it is understood that the present disclosurehas been made only by way of example, and that numerous changes in thecombination and arrangement of parts can be resorted to by those skilledin the art without departing from the spirit and scope of the invention,as hereinafter claimed.

1. A global video checker apparatus, comprising: a global video checkfor cadence with repeat field unit; a global video check for cadencewithout repeat field unit; a multiplexer coupled to the global videochecker for cadence with repeat field unit and the global video checkerfor cadence without repeat field unit; and a temporal control unitcoupled to the multiplexer.
 2. The apparatus of claim 1, wherein themultiplexer is configured to receive a cadence signal and select a videofallback mode flag provided from the global video check for cadence withrepeat field unit or the global video check for cadence without repeatfield unit based on the cadence signal.
 3. The apparatus of claim 2,wherein the cadence signal is provided by an external unit.
 4. Theapparatus of claim 1, wherein the temporal control unit is configured toreceive video fallback mode flags from a plurality of fields and providea temporally converged video fallback mode flag.
 5. The apparatus ofclaim 1, wherein the global video check for cadence with repeat fieldunit comprises: an inter-frame motion detector; a repeat field motiondetector coupled to the inter-frame motion detector; a summing unitcoupled to the repeat field motion detector; and a video fallback modedecision unit coupled to the summing unit.
 6. The apparatus of claim 5,wherein the inter-frame motion detector is configured to provideinter-frame motion signals.
 7. The apparatus of claim 5, wherein theinter-frame motion detector is shared with an external unit.
 8. Theapparatus of claim 5, wherein the repeat field motion detector isconfigured to compare a plurality of inter-frame motion values in aneighborhood window with a motion threshold when a current field is arepeat field and provides a detected repeat field motion flag for acenter pixel of the neighborhood window based on a density of motion ina local window.
 9. The apparatus of claim 8, wherein the repeat fieldmotion detector is configured to provide the detected repeat fieldmotion flag according to the equations.${MRpt} = \left\{ {{\begin{matrix}1 & {{\left( {{M\; 13_{0,0}} > {MRptTh}} \right)\&}\mspace{14mu} \begin{pmatrix}\left. \left( {{cnt} \geq {MRptSumTh}} \right) \right| \\\left( {c_{0} \geq {MRptColTh}} \right)\end{pmatrix}} \\0 & {otherwise}\end{matrix}{where}{cnt}} = {{{\max\left( {{\sum\limits_{j = {- 1}}^{1}c_{j}},{\sum\limits_{i = {- 1}}^{i}r_{i}}} \right)}{and}r_{i}} = {{{\sum\limits_{j = {- 2}}^{2}{\left( {{M\; 13_{i,j}} > {MRptTH}} \right)\mspace{14mu} i}} \in {\left\lbrack {{- 1},1} \right\rbrack c_{j}}} = {{\sum\limits_{i = {- 2}}^{2}{\left( {{M\; 13_{i,j}} > {MRptTh}} \right)\mspace{14mu} j}} \in {\left\lbrack {{- 1},1} \right\rbrack.}}}}} \right.$10. The apparatus of claim 5, wherein the summing unit accumulates aplurality of detected repeat field motions and provides a repeat fieldmotion sum.
 11. The apparatus of claim 5, wherein the video fallbackmode decision unit compares a repeat field motion sum with a userdefined threshold.
 12. The apparatus of claim 1, wherein the globalvideo check for cadence without repeat field unit comprises: afeathering detector; a tail detector; and a video fallback mode decisionunit coupled to the feathering detector and the tail detector.
 13. Theapparatus of claim 12, wherein the feathering detector comprises: aninter-frame motion detector; a field buffer; a second multiplexer; avertical frequency analysis unit coupled to the second multiplexer; amotion adaptiveness unit coupled to the field buffer and the verticalfrequency analysis unit; a vertical frequency post-processing unitcoupled to the motion adaptiveness unit; and a summing unit coupled tothe vertical frequency post-processing unit.
 14. The apparatus of claim13 further comprising a comparator coupled to the inter-frame motiondetector, wherein the field buffer is coupled to the comparator.
 15. Theapparatus of claim 13, wherein the inter-frame motion detector is sharedwith an external unit.
 16. The apparatus of claim 13, wherein thevertical frequency analysis unit is configured to provide detectedfeathering values from a plurality of pixels from a current field and acoupling field.
 17. The apparatus of claim 16, wherein the verticalfrequency analysis unit is configured to provide the detected featheringvalues according to the equations${vfreq}_{i} = \left\{ {{{\begin{matrix}{{freq}_{k,1} - {freq}_{k,2}} & {{fielddiff}_{k} \geq {MonotoneTh}} \\0 & {otherwise}\end{matrix}k} = 0},1,{{2{where}\text{}{freq}_{k,1}} = {{\sum\limits_{i = 0}^{3}{\left( {{\left( {y_{k + i} - {mean}_{k}} \right) \cdot \left( {y_{k + i + 1} - {mean}_{k}} \right)} < 0} \right){freq}_{k,2}}} = {{\sum\limits_{i = 0}^{2}{\left( {{\left( {y_{k + 1} - {mean}_{k\;}} \right) \cdot \left( {y_{k + i + 2} - {mean}_{k}} \right)} < 0} \right){mean}_{k}}} = {{{\left( {{\left( {y_{k} + y_{k + 2} + y_{k + 4}} \right) \times 2} + {\left( {y_{k + 1} + y_{k + 3}} \right) \times 3} + 6} \right)/12}{and}{fielddiff}_{k}} = {{{{{{\left( {y_{k} + y_{k + 2} + y_{k + 4}} \right) \times 2} - {\left( {y_{k + 1} + y_{k + 3}} \right) \times 3}}}/12}{vf}} = \left\{ \begin{matrix}{\max \left( {{vfreq}_{0},{vfreq}_{1}} \right)} & {{currfield} = {top}} \\{\max \left( {{vfreq}_{1},{vfreq}_{2}} \right)} & {{currfield} = {{bottom}.}}\end{matrix} \right.}}}}}} \right.$
 18. The apparatus of claim 13,wherein the motion adaptiveness unit is configured to provide a movingfeathering signal from a detected feathering value and inter-framemotion values at time t and t−1.
 19. The apparatus of claim 18, whereinthe motion adaptiveness unit comprises: a max operator; and a thirdmultiplexer coupled to a max operator, wherein the max operator isconfigured to receive recursive inter-frame motions and provide to thethird multiplexer a maximum motion value; and wherein the thirdmultiplexer is configured to output the detected feathering value as themoving feathering signal if the maximum motion value is classified asmotion or ‘0’ otherwise.
 20. The apparatus of claim 13, wherein thevertical frequency post-processing unit is configured to provide apost-processed feathering value from a plurality of moving featheringvalues in a local neighborhood window.
 21. The apparatus of claim 20,wherein the vertical frequency post-processing unit is configured toprovide the post-processed feathering values according to the equations${vf}^{''} = \left\{ {{\begin{matrix}{vf}^{\prime} & {{\left( {{vf}_{0,0}^{\prime} > {VFTh}} \right)\&}\mspace{14mu} \begin{pmatrix}\left. \begin{pmatrix}{\left( {{sum} \geq {VFSumTh}} \right)\&} \\\left( {{rcnt} = {true}} \right)\end{pmatrix} \right| \\\left( {c_{0} \geq \left( {{VFColTh} \times 4} \right)} \right)\end{pmatrix}} \\0 & {otherwise}\end{matrix}{where}{sum}} = {{\sum\limits_{j = {- 2}}^{2}{c_{j}c_{j}}} = {{\sum\limits_{i = {- 2}}^{2}{{vf}_{i,j}^{\prime}{and}{rcnt}}} = {{\begin{pmatrix}{{{\left( {r_{- 2} \geq {VFRowTh}} \right)\&}\mspace{14mu} \left( {r_{- 1} \geq {VFRowTh}} \right)}\&} \\{{{{\left( {r_{0} \geq {VFRowTh}} \right)\&}\mspace{14mu} \left( {r_{- 1} \geq {VFRowTh}} \right)}\&}\mspace{14mu} \left( {r_{2} \geq {VFRowTh}} \right)}\end{pmatrix}r_{i}} = {{\sum\limits_{j = {- 2}}^{2}{\left( {{vf}_{i,j}^{\prime} > {VFTh}} \right)\mspace{14mu} i}} \in \left\lbrack {{- 2},2} \right\rbrack}}}}} \right.$22. The apparatus of claim 12, wherein the tail detector comprises: aninter-field motion detector; a global detail estimator coupled to theinter-field motion detector; a tail analysis unit coupled to the globaldetail estimator; a tail post-processing unit coupled to the tailanalysis unit; and a summing unit coupled to the tail post-processingunit.
 23. The apparatus of claim 22 further comprising a pre-filter,wherein the inter-field motion detector is coupled to the pre-filter.24. The apparatus of claim 22, wherein the global detail estimatorcomprises: an average operator configured to provide an average ofinter-field motions at times t−3 and t−1; a min operator coupled to theaverage operator configured to select a minimum value of the average andan inter-field motion at time t−2; and a thresholding unit coupled tothe min operator configured to compare the minimum value with a set ofthresholds and select a classified global detail level.
 25. Theapparatus of claim 22, wherein the tail analysis unit comprises: a firstadder coupled to a first multiplexer; a second adder coupled to a secondmultiplexer; a third multiplexer; a comparator and sign unit coupled tothe first adder and the third multiplexer; a sign unit coupled to thesecond adder; a sign comparator coupled to the comparator and sign unitand the sign unit; an absolute operator coupled to the first adder; afourth multiplexer coupled to the sign comparator and the absoluteoperator.
 26. The apparatus of claim 22, wherein the tailpost-processing unit is configured to detect a strength and density of atail motion and a feathering value in a local neighborhood window andprovide a post-processed tail motion.
 27. The apparatus of claim 26,wherein the tail post-processing unit is configured to provide thepost-processed tail motion according to the equations${tail}^{\prime} = \left\{ {{\begin{matrix}1 & {{\left( {t > 0} \right)\&}\mspace{14mu} \left( {v > 0} \right)} \\0 & {otherwise}\end{matrix}{where}t} = {{{{{\left( {{tail}_{i,j} > 0} \right)\&}\mspace{14mu} \left( {{\sum\limits_{i = {- 2}}^{2}r_{i}} \geq {TailCntTh}} \right)}\&}\mspace{14mu} \left( {{\sum\limits_{i = {- 2}}^{2}\left( {r_{i} > 0} \right)} \geq {TailCntInRowTh}} \right)r_{i}} = {{{\sum\limits_{j = {- 2}}^{2}{\left( {{tail}_{i,j} > 0} \right)\mspace{14mu} i}} \in {\left\lbrack {{- 2},2} \right\rbrack {and}v}} = {{{\left( {{\sum\limits_{i = {- 2}}^{2}s_{i}} \geq {TailVFCntTh}} \right)\&}\mspace{14mu} \left( {{\sum\limits_{i = {- 2}}^{2}\left( {s_{i} > 0} \right)} \geq {TailVFCntInRowTh}} \right)s_{i}} = {{\sum\limits_{j = {- 2}}^{2}{\left( {{vf}_{i,j} > {TailVFTh}} \right)\mspace{14mu} i}} \in {\left\lbrack {{- 2},2} \right\rbrack.}}}}}} \right.$28. A method of film/video mode processing, comprising: detecting filmmode at a global level; detecting video mode at the global level if filmmode at the global level is detected; and detecting video mode at alocal level if video mode at the global level is detected.
 29. Themethod of claim 28 further comprising: processing global videode-interlacing after detecting film mode at the global level if filmmode is not detected at the global level; processing global inversetelecine after detecting video mode at the global level if video mode isnot detected at the global level; and processing local fading betweeninverse telecine and video de-interlacing after detecting video mode atthe local level.
 30. The method of claim 28, wherein detecting videomode at the global level comprises: detecting video mode at the globallevel for cadence with repeat field; detecting video mode at the globallevel for cadence without repeat field; selecting a detection resultbased on a detected cadence; and applying temporal control to selecteddetection results from a plurality of fields.
 31. The method of claim30, wherein detecting video mode at the global level for cadence withrepeat field comprises: detecting inter-frame motion; detecting repeatfield motion from a plurality of the detected inter-frame motions;summing a plurality of the detected repeat field motions; and comparinga sum with a user defined threshold.
 32. The method of claim 30, whereindetecting video mode at the global level for cadence without repeatfield comprises: detecting and summing feathering values in a pluralityof fields; detecting and summing tail values from a plurality of fields;and comparing feathering and tail values sums with respective userdefined thresholds.
 33. A film/video mode processing apparatus,comprising: a global film mode detecting unit configured to activateglobal video de-interlacing if global film mode is not detected; aglobal video checker unit configured to activate global inverse telecineif global video mode is not detected; and a local video detecting unitconfigured to activate local fading between inverse telecine and videode-interlacing.
 34. A television (TV) and/or a set-top-box (STB) devicecomprising the film/video mode processing apparatus of claim 33.